Robbie, Thanks for the info about www.navaching.com. Just what I needed. I understand pipe dimensions -- what I don't know how to do is make a "flue" like in an organ pipe. Making a PVC pipe sound with buzzing lips is one thing, making it sound without a human is another thing. How can I make a PVC pipe sound with a blower? Grant Woodside [ A simple plastic whistle is described at [ http://mmd.foxtail.com/Tech/klein_whistle.html [ A traditional steam calliope whistle design is shown at [ http://mmd.foxtail.com/Calliope/davis.html [ Air calliope whistles of ABS & Lexan supports: [ http://mmd.foxtail.com/Calliope/newAge/index.html [ Search for 'plastic' at [ http://mmd.foxtail.com/archives/KWIC/P/pipes.html [ Search for 'organ' at [ http://mmd.foxtail.com/archives/KWIC/P/pvc.html [ RPVC = Rigid Polyvinyl Chloride [ http://www.plasticsusa.com/rpvc.html [ -- Robbie